Airvida L1 - Features of the Invisible Protective Cover: Built-in Rechargeable Battery - 32-Hour Long Battery Life This compact yet long-lasting built-in battery provides up to 32 hours of use on a single charge. It can be easily charged using a USB cable. Advanced Purification Technology The Airvida L1 is designed to remove harmful particulate matter such as PM2.5 and allergens (pollen, pet dander, etc.). Its powerful purification technology creates a healthier daily environment by ensuring optimal air quality. Quiet and Safe Operation Fanless and filterless design for comfortable, simple, and quiet operation. Airvida complies with CE standards, and its radiation and current are far below EU regulatory limits. Furthermore, Airvida uses silicone material widely used in medical devices, effectively preventing skin allergies. No Additional Consumables Required, Airvida L1 Makes Your Air Purification Process More Convenient. Unlike traditional purifiers, it requires no filters or special maintenance to enjoy a continuous and effortless air purification experience. The Airvida L1 is a stylish and portable personal air purifying necklace with a patented dual-vent design. This ergonomic device continuously releases 20,000,000 negative ions per cubic centimeter, 100 times the concentration of negative ions in a forest. Thanks to its unique "breathing channel ecological ion technology," the released negative ions stay around your face, purifying the air you breathe. In short, it's a small, portable, and comfortable air purifier.